P1

function X = P1(N)
RuleForF = 'F-b+FF-F-FF-Fb-FF+b-FF+F+FF+Fb+FFF';
X = 'F-F-F-F';
teta = pi/2;
alfa = 0;
m=1;
n=1;
i=1;
j=1;
while i<N+1
len_X = length(X);
while j<len_X+1
if X(j) == 'F'
while m<length(RuleForF)+1
H(n) = RuleForF(m);
m=m+1;
n=n+1;
end
elseif X(j)=='-'
H(n) = '-';
n=n+1;
elseif X(j) =='+'
H(n) = '+';
n=n+1;
end
m=1;
j=j+1;
end
i=i+1;
X=H;
j=1;
n=1;
end
line = animatedline; i=2;j=1;
x(1)=0;
y(1)=0;
addpoints(line,x(1),y(1));
drawnow
while j<length(X)+1
if X(j) == 'F'
x(i) = x(i-1)+cos(alfa);
y(i) = y(i-1)+sin(alfa);
addpoints(line,x(i),y(i));
i=i+1;
drawnow
elseif X(j)=='-'
alfa = alfa-teta;
elseif X(j) =='+'
alfa = alfa+teta;
end
j=j+1;
end
end